From the Webroot Threat Blog:
Recently we have seen an increase in fake Microsoft scams, which function by tricking people into thinking that their PC is infected. With these types of scams there are a number of things to remember.
1. Microsoft will never call you telling you that your PC is infected
2. Never allow strangers to connect to your PC
3. Do not give any credit card info to somebody claiming to be from Microsoft
4. If in doubt, shut down your PC
The current scam will display a webpage that is very similar to the one in Figure 1. There are a number of ways to figure out that this is a false alert. The first is that it's a website message and not a program; the second is that location of the web site will be a random string of letters.
Continued : http://blog.webroot.com/2013/04/30/fake-microsoft-security-scam/
Light bulbs you shouldn't buy
There are plenty of dimmable LED light bulbs, but make sure you don't buy the ones that flicker when you dial them down.